The Brown County Sheriff's Office has a message for people looking to purchase sex in our area: "Buyer beware."

That's what Chief Deputy Todd Delain said Thursday during a news conference on a recent human trafficking sting in the county.

"If you're a buyer looking for sex in Brown County, buyer beware," Delain said. "You might be dealing with a law enforcement officer that's looking to arrest you."

Thirty-five men were taken into custody over the course of a 4-day operation, between Monday, July 17, and Thursday, July 20.

The arrests were made in conjunction with the Green Bay Police Department, De Pere Police Department, Ashwaubenon Public Safety Department, Brown County Drug Task Force, Wisconsin Department of Justice and the Federal Bureau of Investigation.

"About 99.9 percent of the stuff we do is on the internet, whether it be Backpage, Craigslist, or any other escort internet websites that we use," Sgt. Matthew Wilson of the Brown County Sheriff's Office, said.

Authorities said the operation was in support of the National Johns Suppression Initiative which started in Cook County Illinois in 2011.

"This doesn't stop our day-to-day operations of going after trafficking victims as well as the traffickers themselves," Sgt. Wilson said. "So this was just an initiative that we were working on in collaboration with the Cook County Sheriff's Office to go after the sex buyers themselves."

Undercover investigators say pimps and Johns often ask questions or make demands:

"Are you sure you're not a cop?""Take a picture so I know it's you."

Sgt. Wilson says catching pimps turns into a game of cat and mouse.

"They do one thing and then we find a way to combat it. They do another thing, we find a way to combat it. It's just a matter of they know we're out here, they know we're doing this, but it's not stopping them because it makes them money," Wilson said.

Chief Deputy Delain said the goal is to target sex buyers and direct victims to resources in the community.

During Thursday's news conference, officials highlighted the signs of someone who may be a victim of sex trafficking:

Unexplained absence from school

Talks of wild parties and sexual behavior

Displays of expensive clothing and jewelry

Inappropriate dress

Significantly older boyfriends or girlfriends

Withdrawn, depression and distraction

Signs of abuse, such as burn marks, cuts, bruises, or new tattoos (signs of branding)

The National Johns Suppression Initiative is aimed at cutting the demand to lower the number of young women solicited for sex.

Of the victims, 70 percent are in foster care or similar circumstances.

"Young females, 12-14 years of age, that have problems at home, that don't have any parental guidance or anything like that guidance or anything like that," Sgt. Wilson said.

Victim advocates provide resources for the young girls.

"Mental health is a big part of that, and of course traffickers are looking for someone that is incredibly vulnerable," says Shelby Mitchell, Sex Trafficking Victim Advocate, Family Services.

Dawn Sprang is the after care director at Eye Heart World.

"Sometimes it's for food, sometimes it's for housing, sometimes it's for drugs," Sprang said. "So we look at each individual situation and look at what they need and then we help connect them to resources out in the community based on those needs."

The national operation happened between June 28 and July 31 involving 37 law enforcement agencies across 17 states.